Improvement in dovetailing-machines



3 Sheets--Sheet i. A. S. GEAR & B. F. DU NKLEE.

Improvement in Dovetailing Machines.

No. 125,282, Patented April2,18?2, I

II llbll H Tr H II II III?! I] 3 Sheets--Sheet 2. A. s. GEAR-18L 3. f,

Improvement in Dovefaiiing Machines.

No. %25,282 PateritedApril2,1872.

3 Sheets SheeT 3. A. s. GEAR & B. F. DUNKLEE.

Improvement in Dovetailing Machines.

No. 125,282, PatentedApril2,1872.

ter-turn belt, 0, driven from any suitable pulley FFIOE.

ALONZO S. GEAR, OF BOSTON, MASSACHUSETTS, AND BEN F. DUNKLEE, OF CONCORD, NEW HAMPSHIRE, ASSIGNORS TO SAID ALONZO S. GEAR.

IMPROVEMENT IN DOVETAlLING-MACHINES.

Specification forming part of Letters Patent No. 125,282, dated April 2, 1872.

To all 'urhom it may concern:

Be it known that we, ALoNzo S. GEAR, of Boston, in the county of Suffolk and State of Massachusetts, and BEN F. DUNKLEE, of Concord, Merrimac county, New Hampshire, have invented an Improved AutomaticallyOperating Dovetailing-Machine; and we do hereby declare that the following, taken in connection with the drawing which accompanies and forms part of this specification, is a description ofourinven tion sufticientto enable those skilled in the art to practice it.

This invention relates to automatic devices for cutting dovetailed mortises and tenons, after the manner described in the United States Patent N 0. 99,446, dated February 1, 1870. By said automatic devices, after the material is arranged and clamped it is presented and moved properly with reference to a suitably-shaped rapidly-rotating cutter, (preferably such a one as is shown and described in the United States Patent No. 103,750, dated May 31, 1870,) with out use of a former or pattern, against a guide on the cutter-spindle, and without manipulatory guidance on the part of the operator, and so that a series of any desired number of mortises and pins or tenons are cut by one cutter and one operation, in two pieces of material, in constant succession, without cessation, until the formation of the series is complete or, at the will of the operator, so that mortises alone are formed in one piece and tenons in the other, in which case but one piece at a time is operated upon.

A machine embodying this invention is shown in front elevation in Figure 1, in side elevation in Fig. 2, and in plan in Fig. 3.

I The cutter a is rotated rapidly by motion given the vertical shaft 1) by means of a quard, the cutter-shaft I) being mounted in suitable bearings fixed to a frame or carriage, e, which is guided in ways f, (fixed to the machineframe g,) and made to move up and down thereon by manipulation of the screw h. On the upper part of frame g is a compound carriage for presenting and moving the material to be dovetailed. The lower part 'i of said carriage is fitted to reciprocate on guide-rails 7', and is provided with guides at right angles to guides j, to receive and guide the upper part 7c of the compound carriage. This upper part k of they compound carriage is provided with clamps, by which the wood pieces are clamped in proper position so as to receive, without motion relative to the carriage, the action of the cutter. When two pieces-say the front and one side of a drawer-are to be dovetailed to fit together, then the front or thickest piece n is placed on the plate I of carriage 7c, and the clamp-bar m is forced upon the wood a by the screw 0, which has a nutformed in the piece 19, which extends between the cheeks q of the upper carriage, one face of 19 being square to the wood-sustaining surface of plate I, and making the bed-surface to which the thin piece 1' of wood is clamped by bar 8, which is acted on by screw 25, having its nut in piece a, extending between cheeks q q. The clamp-bars s and on are guided by slides a c, connected by cross-bars 20, against which act springs as to draw from the wood the clampbars when the clamp-screws are retracted, the

springs reacting against bars p and a. To an range the pieces n and r in the clamps to produce a dovetailed joint, like that shown in Fig. 4, the thin piece 1' has its end brought down to the level of the upper surface of plate I, and the end of the thick piece 12 is brought upv against the piece 1, and the edges of said pieces, which, when united, are to be in the same plane, are set over one beyond the other a distance equal to half of the distance apart between the centers of adjacent tenons. The edge of plate lis serrated, to afford support and a gauge to the piece 1', and to pass freely by the cutter-spindle in the movement of the compound carriage.

The movements imparted to the compound carriage are effected by mechanism as follows: A horizontal counter-shaft, 0c, is provided with two wide loose pulleys, 1 located on either side of a narrow pulley, 2, made fast on said shaft; and two belts, one, a, open, and the other, I), crossed, are so arranged that by means of a shipper the shaft :0 will be rotated in either direction, according as one or the otherof the belts a b is in the tight pulley, or will be left at rest if both belts are on the loose pulleys. On the inner end of shaft 00 is fixed a worm or screw 0, which meshes into a worm or screw-gear, d, fixed at the lower end of the vertical shaft e. The upper end of shaft 0 carries a disk in which are fixed a crank-pin, f, and a center-pin, 9, and to the under side of plate lof the upper carriage is fixed aplate, h, having notches which fit about half way around the crank-pin, and elongated notches the width of which is equal to the diameter of the center-pin. The rods 1" are secured to the upper part of the compound carriage, and pass through eyes k fixed to the lower part of the carriage, the rods being surrounded by spiral springs j, between the plate I and the eyes k, and being screw-threaded at the ends and then provided with nuts and check-nuts l. The tendency of the springs j is to push forward the upper part of the compound-carriage, the nuts 1 limiting the extent of the forward movement. The adjustment of the nuts Z being such as to allow the wood to be carried forward upon the cutter as far as desired, the notched plate h is to be adjusted so that while the elongated notches will embrace the centerpin when the crank-pin is out of gear with the shallow notehes,'the center-pin will be released from its encompassing notches whenever the crank has forced back the plate lthe extent required, and then the motion of the crank will. be operative in producing a compound movement of both parts of the slide, resulting in so moving the material to be cut around the cutter as to cut the tenons into counterparts of the mortises. To adjust the position of h, the screws which hold it to plate l are elongated in the direction of the length of the rods i, so that by manipulation the notched plate h can be set so that at the proper point the notched plate will be freed from the control of the center-pin g. From the front of the carriage 6 two pieces, I, extend downward, for the purpose of operating upon rod 012 to work the shipper to stop or reverse the motion of the compound carriage. On said rod are two adjustable collars, n, and between them and the pieces Z are coiled springs to prevent shocks. The shipping motion is made more or less frequent by adjusting the collars nearer to or further from the pieces Z. The lever which works the shipper is connected to the slide-rod m, and one end of the lever projects and forms a handle by which the shipper may be worked at will. The rods 0 are made adjustable, and serve as gauges by which to set the pieces of wood properly in the machine.-

W hen pins or tenons alone, or mortises alone, are to be cut, then the adjustment of the plate h and of the nuts I must be such as to carry the wood clear of the'cuttcr during the compound movement of the parts 70 and i of the carriage, and the direct forward and back movement given to the wood must be sufficient to entirely clear the wood from the cutter. When such movement is two, three, or more times greater than the thickness of the wood to be wrought, then pins or tenons alone, or mortises alone may be formed entirely through two, three, or more pieces of wood, which together are forced against the vertical face of bar 19.

Fig. 4 shows two isometric views of two pieces of wood wrought by one operation with my machine, with dovetailed tenons and mortises, such as are needed for drawer fronts. The view A shows the relation of the two parts of the wood as clamped in the machine and shaped by the cutter. The distance from edge of the wood on which the tenons are formed to the edge 2 of the wood in which the mortises are formed, is equal to one-half of the distance apart of the centers of two adjacent tenons or mortises. To unite the tenons or mortises so formed, bring the edges into the same plane and the outer ends of the tenons into line with the plane surface of the mortises, and then by turning the piece with the tenons thereon one hundred and eighty degrees the parts will mesh together.

The operation of forming dovetails may be carried on from right to left, or vice versa, or in both directions alternately, just as may be deemed most convenient and expeditious by the operator, who, if he desires always to commence operations from one side only, need not wait to feed back the carriage to its startingpoint'by the action of the mechanism, as the operator can, by pushing back the part 70, free plate h from the controlling-pins f g, and then both parts of the compound carriage can be moved by the operator either to the right or left as far as is necessary or desirable.

We claim- The herein-described dovetail-cutting machine, in which the following parts coact to produce in two pieces, located angularly with respect to each other, pins on one piece and recesses in the other, both of the dovetailed form shown, successively, continuously, and automatically, by the cutting action of one tool only, said parts being, first, the rotary cutter-head, having a cutting-edge or edges which in rotation describe the curved surface of a conic frustum; second, the clamps, made to hold angularly with respect to each other two pieces to be wrought by said cutter; third, the carriage, of two parts, bearing said clamps, the said parts being constructed and arranged to be moved at right angles relatively to each other to convey the clamped material forward and back relatively to the cutter, and also in curved directions around it consequent upon joint movement of both parts of the compound carriage in the relative directions aforesaid;

and fourth, the herein-described mechanism for automatically moving both parts of said compound carriage in directions as described.

ALONZO S. GEAR. BEN F. DUNKLEE. Witnesses:

J. B. (JRosBY, L. H. LATIMER. 

